Corrections and clarifications

• An article reporting on a study into the effects of tobacco, published by the Lancet, said it showed that giving up cigarettes before the age of 35 reduced a woman's risk of smoking-related death by 97%. In fact it showed that giving up before the age of 30 reduced the risk by that amount (Death rate treble for women who smoke into middle age, 27 October, page 12).

• A report on the election campaign in the US said 23 out of the 50 states had passed "right-to-work" laws that "prohibit unions from requiring members to pay dues". Right-to-work legislation means that non-members cannot be required to pay any fees to a union, and prevents them being dismissed or otherwise penalised for failing to do so (Obama union workers: 'It's a fight for survival', 29 October, page 14).